Tomatoes are delicious and he althy too. Unfortunately, they are also prone to disease. We have an overview of the 10 most common tomato diseases for you.
Tomatoes are among the most popular vegetables in German gardens. Unfortunately, there are also plenty of diseases that can afflict plants and severely reduce crop yields.
It is important that you check your plants regularly so that you do not have to throw away your valuable harvest. The sooner you notice changes, the sooner you can intervene and fight the pests.
You will find below the most important and most common tomato diseases and how to recognize and combat them.
The 10 most common tomato diseases
1. The fruit rot and stem rot
This rot is caused by a fungus that can penetrate the fruit, especially where the bark is injured. Especially when the weather is damp in summer, the spores of the fungus can spread unhindered, the wind ensures transmission to other plants.
Recognize
You can recognize an infestation by the black spots on the rind of the tomatoes. On larger plants, the area around the stalk can also sink in. Gradually, the plant will wilt and the leaves will turn yellow.
Control
It is better to prevent this disease by regularly rotating crops and not using seeds from the affected tomatoes for further cultivation. The plants should be placed in the bed with sufficient distance from each other to ensure adequate ventilation. The affected parts of the plant must be removed immediately and disposed of with the residual waste - never in the compost. It is also important that you clean the climbing aids thoroughly and destroy the strings that were used to attach the plants.
Late blight is also caused by a fungus. In this case, too, the spread is favored by warm, damp weather, as is the case with dew formation. Especially in August and September you should plant regularly for possiblecontrol infestation. Once an infestation has taken place, there is usually no way to save the plant.
Recognize
The disease is manifested by greyish-green spots on the leaves, the discolouration can range to black. If you look at the underside of the leaves, you will see a greyish or white coating. The leaves often curl up too.
The infestation usually progresses very quickly and the leaves die off. But the fruits and stems can also be affected. Brownish spots appear on the tomatoes, the spots are also hardened and slightly sunken. The fruit then shrivel and rot. Even tomatoes that have already been harvested can rot up to five days later. Toxic substances form in the fruit, which is why the tomatoes are inedible.
Control
When growing, it is important to leave more space between tomato plants. This is the only way to ensure good ventilation and the plants can dry off more quickly after a downpour. You should only ever water the root area.
It would be ideal if you put a small canopy over the bed or decide on a tomato house right away. It is also helpful to apply a layer of mulch so that no moisture gets to the plants from below. You can also make a broth from skimmed milk and spritz the tomatoes with it once a week. To do this, add a pack of skimmed milk to two liters of water. Alternatively, a broth made from onion skins can help.
3. Early Blight
Early blight is also caused by fungi that are spread by the wind. The pathogens also remain in the soil and on the climbing aids for the tomatoes. Potatoes are often the cause of the disease, so potatoes should never be planted next to tomatoes.
Recognize
You can recognize the infestation by the round, grey-brown spots on the leaves. The infestation progresses from bottom to top. If the infestation is very severe, the leaves will die off over time. Later you will also see spots on the stems, but these are more of an elongated shape. The tomatoes will soften and begin to rot from the calyx area.
Fight
It is important that you always clean the wooden sticks to which the tomatoes are tied meticulously at the end of the gardening season. Since humidity also increases the risk of early blight infestation, you should take the same preventive measures as you would for any other fungal diseasemeet.
Powdery mildew, another fungal disease, occurs on many plants in the garden. The tomatoes are not spared either. It doesn't even have to be very humid and warm for the spores to spread unhindered.
Recognize
The infestation is indicated by a white fungal coating on the leaves and their stems. It looks like they're dusted with flour, hence the disease's name.
In the further course, the white spots expand and partially cover the entire sheet. Later, the leaves turn increasingly brown and then dry up. The tomatoes themselves show no symptoms. It has to be said that powdery mildew is rather rare on tomatoes. If an illness occurs, it is often in late summer, so that control is then no longer necessary. Tomato varieties that are relatively resistant to powdery mildew are commercially available. These include, for example, the varieties Philovita or Phantasia F1.
Control
To prevent the spread of the fungal disease, the affected parts of the plant are removed.
5. The Gray Horse
If the humidity is very high in summer, it can lead to an infestation with gray mold. The spores are then transmitted by drafts, but they can also survive in the soil.
Recognize
Grey-green spots of different sizes appear on the leaves and stems of tomato plants. Later you will also see a gray fungus coating on the leaves. If the stem of the plant is badly affected, the whole plant may die.
Control
As to prevent all fungal diseases, the tomato plants should be kept as dry as possible in summer. Sufficient planting distance is important for optimal ventilation and faster drying after rain. The affected plant parts are removed and disposed of with the residual waste, never put them on the compost heap. If you have tomatoes in the greenhouse and gray mold is constantly infesting them, you should thoroughly clean the entire greenhouse.
Several fungi are responsible for the infestation with the so-called damping-off disease. If the humidity is very high and the soil is acidic, then the fungus has an easy time. Other favorable factors are waterlogging and strong compaction of the soil.
Recognize
Above the surface of the earth you can see dark constrictionsrecognizable by the seedlings. Because they don't have enough support, they eventually fall over, hence the name of the disease.
Fight
To prevent this, the potting soil should be mixed with rock flour and sand. You should think about pricking out in good time and water the plants with horsetail broth before moving them. The soil in the beds must never be too wet, because waterlogging would be extremely unfavourable. It is best to use stagnant rainwater for watering, which should not be too cold either.
7. The Blossom End Rot
When tomato plants are deficient in calcium, blossom end rot can occur.
Recognize
Spots can be seen on the older leaves, while the younger ones deform and remain much smaller, as well as taking on a dark green colour. However, you are more likely to recognize the disease on the tomatoes themselves, because they have watery spots on the flower stems. These grow larger over time and turn brown or brown. These areas are often hardened and sink in a bit.
Fight
In order to prevent the disease, care should be taken to ensure that the plants are supplied with water and nutrients evenly. If an infestation has already occurred, you can administer carbonate of lime.
8. Corkroot Disease
Recognition
Unfortunately, this fungal disease can only be recognized late, as it first appears on the roots. Only later do you see wilted leaves, which also remain significantly smaller, at high temperatures. The plant grows very slowly, so the yields are of course correspondingly lower. It's only after harvest time when you remove the plants that you see dead roots that are corky and browned. The fungus stays in the ground for several years and can thus lead to new infections again and again.
Fight
When buying, you should pay attention to particularly robust tomato plants, and crop rotation should also take place regularly. After the end of the harvest season, the bed is dug up as deep as possible and all parts of the plant are carefully removed and disposed of with the residual waste.
9. Velvet Blotch
DetectThis fungal infection only affects tomatoes in greenhouses. If it is very warm and humid there, the fungus finds ideal conditions to spread. Yellow spots can then be seen on the leaves, green-brown spots appear on the underside of the leaves, which look like velvetseem exaggerated. The infestation with this fungus is only visible on the leaves, which are drying up more and more.
Control
To prevent the disease, proceed as with brown rot. If an outbreak has already occurred, only water the tomato plants in the mornings on sunny days. In addition, better ventilation should be provided in the greenhouse. When watering, make sure that you only water the area around the roots; the leaves must remain dry. To allow air to circulate better, you can remove the lower shoots. If the infestation is very severe, you should use a fungicide.
10. The Tobacco Mosaic Virus
Recognize
This fungal disease shows mosaic-like patterns on the leaves and the plant also sheds its flowers. Bronze discoloration occurs on the plant, the tomatoes have brown spots at the end of the stalk. The spots are bronze in the young fruits, inside the tomatoes are corked, brown spots.
Fight
If an infestation occurs, you can no longer save the plant. To prevent it from spreading, it must be removed immediately. In the coming year, the tomatoes should not be planted in the same bed. You can then spray them with a decoction of skimmed milk or onion skins as a preventive measure.